As if there’s not already enough excitement surrounding tonight’s 12-12-12 Concert for Hurricane Sandy relief, the show’s stacked lineup of artists are expected to perform together – reportedly Paul McCartney and Dave Grohl will “jam with some mates” of the former Nirvana drummer, The Guardian confirms.

Spin, on the other hand, received a “we can neither confirm nor deny” response from Nasty Little Man, the publicity firm representing both McCartney and Grohl in the U.S. When reached by CBS Local for a comment, a rep gave a “wait and see tonight” response.

Another, less reputable, source took that rumor one step further in an earlier report: UK’s The Sun is saying that McCartney is going to lead some sort of Nirvana reunion, playing the role of Kurt Cobain (and by “role” they mean he will be singing). The Sun claims that Macca and Grohl, who played together at the 2012 and 2009 GRAMMYs (and other times through the years), have been secretly working together, along with Nirvana bassist Krist Novoselic and Pat Smear, Foo Fighters guitarist and Nirvana touring member. McCartney reportedly suggested the group “just make something up,” not realizing that he was somehow part of pseudo Nirvana reunion (note: Novoselic has collaborated with Grohl’s Foo Fighters previously – they’re not exactly long-lost bandmates).

The report goes on to say that the group will play a new song tonight at the 12-12-12 Concert. But what if they played some old Nirvana songs too? We can’t envision Macca screeching through “Smells Like Teen Spirit,” but “In Bloom” and “About a Girl” already have slight throwback pop vibes. “Heart Shaped Box” is a little dark for McCartney, but then again, so is everything Nirvana ever released.

The 12-12-12 Concert also includes the Rolling Stones, Bruce Springsteen, The Who, Eric Clapton, Bon Jovi, Billy Joel, Kanye West, Alicia Keys, Chris Martin of Coldplay, Eddie Vedder of Pearl Jam, and Roger Waters of Pink Floyd. The show kicks off live from NYC’s Madison Square Garden starting at 7:30 p.m. tonight, and will be broadcast on 34 TV channels stateside, as well as internationally, and streamed online.

What song would you like to see Paul and Nirvana’s surviving members perform? Tell us in the comments.

- Jillian Mapes, CBS Local